Pick out a couple of projects to work on and familiarise yourself with them, or bring your own project(s) to work on. See the projects page for a list of projects people plan to work on. If you plan to work on your own project, be sure to list it on the projects page and set up a public repository if you don't already have one, so that other people can help hack on your project.

Install an up to date Haskell toolchain: at least ghc (preferably 6.10.*) and cabal-install. If you don't already have these installed (or need to install from scratch on the laptop you're bringing), the easiest way is probably to install the Haskell Platform.